Saturday, July 23, 2016

Here's a table with the aero choices made by the 20 fastest riders on the day. As far as I can tell all rode using a skin suit (although some of the suits were not exactly a good aero fit). Note - I've updated Mollema's entry a few hours later as he was using a rear disk wheel.

Note: Rodriguez swapped from a time trial bike to a road bike part way along.

This suggests all these riders recognised that aerodynamics still mattered, but not enough that riders thought it worth using some other basic aero kit. Perhaps they felt there was too much of a weight penalty (there's not BTW). Or they did not feel good climbing on a TT bike, or were concerned with the descent? Lack of preparation is my take.

For reference, I used photos from the various websites to work out who used what. For front wheel and helmets, there might be a little debate as to it fits the category of aero or not. Needed to be a full aero TT helmet to count and what looked like low-ish profile wheels went in the "No" category. Always happy to amend if people spot errors.

Richie Porte, with not even an aero front wheel, let alone an aero helmet:

Fabio Aru, not much better:

Contrast with the stage winner Chris Froome who used all the aero aids at his disposal:

Average speeds for the top 20 ranged from 31.5km/h to 33.2km/h. Aerodynamics still matters quite a bit at such speeds. So why not take advantage of it?

Yes it was hilly but the lack of aero equipment choices for a TT even at these speeds does rather bemuse me. Weight penalty of helmets and wheels is negligible and any small benefits are outweighed by aero losses.

3
comments:

Well there is already plenty of published data on RRC, so making such choices then becomes a case of optimising the CdA/RRC balance. Main problem many face is requirements to ride sponsor's kit when it's not optimal.

Tyre pressures as we know are often over inflated (old school beliefs), and again there is good data available for anyone that cares to take notice.

Bearings are a tiny fraction of power demand, so even halving the bearing drag isn't helping all that much. Probably one of the most expensive per watt saved but if you already have them and they are well maintained, then why not?

I agree with your sentiments that a lot of the GC riders should have done better with their approach to aero. The only comment I'd make is, that stage was an extremely windy day, a number of riders were affected by the cross winds, and the couple I saw were blown across the road. So I can understand why some riders such as Richie and Aru adopted a safer approach than risking completely coming off.

I was surprised that more didn't adopt for a shallow front wheel and either a disc or deep rim rear.That being said, it probably highlights how impressive Froome and Dumoulin rode with their aero get up.